Contours again.

[Ed McNierney]

Bob -

After you run shptree you will see a new file with a .qix extension.  You should then rerun your tests and see a difference.

     - Ed

----- Original Message -----
From: Bob Basques <bob.basques at ci.stpaul.mn.us>
To: Ed McNierney <ed at TOPOZONE.COM>
Sent: Thu, 14 Oct 2004 11:05:02 -0400
Subject: Re: Contours again.


> Ed McNierney wrote:
> 
> >Bob -
> >
> >I'm not entirely sure from your reply that you understood that Armin's f=
> >irst suggestion is to simply use shptree to create a spatial index for y=
> >our single shapefile.  In the directory where your shapefile is stored, =
> >simply use the command
> >
> >    shptree shapefile.shp
> >  
> >
> I tried this and nothing is produced, the prompt sits there (crewating 
> index of new  LSB format) for a while then just returns.
> 
> I'm running on REDHAT Fedora Core.
> 
> Is there some special syntax to look out for?
> 
> Some notes:  I have the data on a NAS mounted on the WebServer.  I'm 
> running the SHPTREE command on the Server into the home directory of the 
> login.  Don't know if this might be causing write problems or not.
> 
> >and a file with the same base name and the extension .qix will be create=
> >d.  Then you can run your test again - creating the index will just take=
> > a few moments and you don't have to do anything with your data organiza=
> >tion.
> >
> >I'm assuming, by the way, that your test request is actually displaying =
> >only a small portion of the entire shapefile.
> >
> Yup, I plan on making a couple of generalized layers for the wider area 
> views.
> 
> >  If you're trying to draw =
> >the entire 550 MB shapefile in a single image, you have different proble=
> >ms <g>.
> >  
> >
> Nope.  Just trying to see if this is going to be a performance problem 
> or not right now.
> 
> bobb
> 
> >     - Ed
> >
> >Ed McNierney
> >TopoZone.com
> >
> >----- Original Message -----
> >From: Bob Basques <bob.basques at CI.STPAUL.MN.US>
> >To: MAPSERVER-USERS at LISTS.UMN.EDU
> >Sent: Wed, 13 Oct 2004 17:56:00 -0400
> >Subject: Re: [UMN=5FMAPSERVER-USERS] Contours again.
> >
> >
> >  
> >
> >>Armin Burger wrote:
> >>=20
> >>    
> >>
> >>>Bob,
> >>>
> >>>you could also try just creating a spatial index for the shapefile us=
> >>>      
> >>>
> >ing s=3D
> >  
> >
> >>>hptree. 2 minutes looks like there is no existing spatial index and m=
> >>>      
> >>>
> >ore o=3D
> >  
> >
> >>>r less all features of the shapefile are read all the time.
> >>>
> >>>      
> >>>
> >>Yes I think this is correct.
> >>=20
> >>    
> >>
> >>>Maybe this ind=3D
> >>>ex already speeds up things sufficiently.
> >>>
> >>>Instead of splitting up the contour lines into seperate shapefiles th=
> >>>      
> >>>
> >at ha=3D
> >  
> >
> >>>ve then to be put together with a shapeindex, it might be an alternat=
> >>>      
> >>>
> >ive t=3D
> >  
> >
> >>>o intersect the contour lines with a regular grid. E.g. like the shee=
> >>>      
> >>>
> >ts fo=3D
> >  
> >
> >>>r topographic maps or a rectangular one with arbitrary extent you cre=
> >>>      
> >>>
> >ate o=3D
> >  
> >
> >>>n your own. That way very long lines with huge amount of vertices are=
> >>>      
> >>>
> > spli=3D
> >  
> >
> >>>t up into smaller chunks.
> >>>
> >>>      
> >>>
> >>I actually started out with something like that in the AutoCAD world.
> >>Each tile (1/2 sq. mile) was brought together into a single coverage. =
> >>    
> >>
> > I
> >  
> >
> >>didn't do any joins on the linework, I just let them be seperate
> >>entities.  I figured that was better than joining them anyway.
> >>=20
> >>    
> >>
> >>>The time to read such features is much less than=3D
> >>>for the large ones, but you still have everything in a single shapef=
> >>>      
> >>>
> >ile.
> >  
> >
> >>>If you want just display the values as integer, it might be the easie=
> >>>      
> >>>
> >st wa=3D
> >  
> >
> >>>y to add a new integer column in the dbf file and copy the values fro=
> >>>      
> >>>
> >m the=3D
> >  
> >
> >>>float column. And then use the new integer column  for the labeling.
> >>>
> >>>
> >>>      
> >>>
> >>Good idea, although I think I'll just get rid of the old column
> >>afterwards.  I tried some things with the data writer(AutoCAD Map) but
> >>nothing seemed to help with the labelling.
> >>=20
> >>I think your idea will work though.  I can load the DBF up and add a
> >>column easy enough.
> >>=20
> >>Thanks for the suggestions
> >>=20
> >>bobb
> >>=20
> >>    
> >>
> >>>armin
> >>>
> >>>
> >>>
> >>>      
> >>>
> >>>>All,
> >>>>
> >>>>
> >>>>        
> >>>>
> >>>
> >>>      
> >>>
> >>>>Well I tried out a composite file before asking this question.
> >>>>
> >>>>
> >>>>        
> >>>>
> >>>
> >>>      
> >>>
> >>>>I just ran a 550+meg SHP file for our Contour data.  There is only o=
> >>>>        
> >>>>
> >ne
> >  
> >
> >>>>attribute in the DBF, which is the elevation.
> >>>>
> >>>>
> >>>>        
> >>>>
> >>>
> >>>      
> >>>
> >>>>a Typical request takes around 120 sec to complete.  so I'm going to=
> >>>>        
> >>>>
> > try
> >  
> >
> >>>>and tile the shp file out into smaller version and use a tile index =
> >>>>        
> >>>>
> >on
> >  
> >
> >>>>top of that.  Are there any pitfalls I should watch out for during t=
> >>>>        
> >>>>
> >he
> >  
> >
> >>>>process of tiling a SHP file=3F
> >>>>
> >>>>
> >>>>        
> >>>>
> >>>
> >>>
> >>>      
> >>>
> >>>>Also, how do I label with a INTEGER vs a REAL for the elevations.  I=
> >>>>        
> >>>>
> >'m
> >  
> >
> >>>>getting  14 decimal places in the labels.  :c)
> >>>>
> >>>>
> >>>>        
> >>>>
> >>>
> >>>
> >>>      
> >>>
> >>>>Thanks
> >>>>
> >>>>
> >>>>        
> >>>>
> >>>
> >>>      
> >>>
> >>>>bobb
> >>>>
> >>>>
> >>>>        
> >>>>
> >>>
> >>>      
> >>>
> >>=20
> >>    
> >>
> >
> >  
> >
> 
>